1. Field of the Invention
The present invention relates to the art of reducing fuel consumption and noise of an engine driving a construction machine such as a hydraulic shovel.
2. Background Art
Conventionally, various prior art for the purpose of improving work of a hydraulic shovel is disclosed and known.
In order to improve shovel work, there exists various methods and devices to improve the efficiency of hydraulic circuit structure driving vertical movement of a boom and an arm of a hydraulic shovel and turning of a main body of the hydraulic shovel so as to reduce fuel consumption, there also exists various methods and devices that ration flow amount of a hydraulic pump of a hydraulic circuit driving vertical movement of a boom and an arm of a hydraulic shovel so as to reduce output loss and reduce fuel consumption. Several of these methods are disclosed by the applicant of the present invention and are well-known.
In an embodiment, in order to improve traveling a hydraulic vehicle has low or high traveling speed switching function or automatic two-speed function which reduces shock at the time of stopping of low speed traveling. Embodiments improving output of a hydraulic pump driving a traveling system at the time of traveling are disclosed.